Brake pressure control unit with hydraulic power booster including

Abstract

A brake pressure control unit operable by a hydraulic brake power booster and functionally corresponding to a tandem master cylinder for two statically pressurizable brake circuits has two casing bores spaced laterally apart. In one of the bores, the primary output pressure space bounded by the primary piston and floating piston is accommodated, and in the second bore, a piston which is also a floating piston, bounds the secondary output pressure space by a piston flange. The floating piston bounding the primary output pressure space on one side has the effect of building up, in the end control pressure spaces of the first and second bores, the control pressure acting on the second floating piston. This pressure leads to a displacement of the second floating piston in the sense of a pressure build-up in the secondary pressure space. The second floating piston is connected to a double-acting hydraulic cylinder, which is likewise accommodated in the second casing bore. By alternative pressurization and relief of working spaces of the hydraulic cylinder taking place via electrically controllable valves, antilocking and propulsion regulation functions are made possible in the brake circuit connected to the secondary output pressure space. The primary piston of the brake pressure control unit has an annular piston and a plunger piston, having annular seals which impart reciprocal sealing and also sealing from the primary piston bore. By these annular seals, axially extending, coaxially arranged separating spaces are bounded, these spaces imparting an effective media separation between the hydraulic booster circuit and the primary brake circuit.